October 10, 2006

Astrophysicists Graveyard

Three of the most prominent astrophysicists of the early 20th century are honored in the naming of large craters on the western limb. Of course, because the good craters have long been taken, these are all ruins, mostly rims with interiors buried by mare lavas. Struve, Russell and Eddington range from 100 to 170 km in diameter, and would be dramatic features if their walls had held out the rising lavas of Oceanus Procellarum. Or maybe not, for many unbreached craters (think Plato and Archimedes) are flooded by lavas, but rarely enough to overtop the rim (excepting Wargentin). The rim of Eddington (the eastmost crater) slopes from a northern high point to a few protruding peaklets in the south, suggesting that the crater formed on sloping terrain. The roughness on the southern part of the floor of Struve is debris from Orientale, and a broad swell is near the northwestern part of the floor. Paolo’s image picks up the shadow of a rille in northern Eddington that shows on the Lunar Orbiter IV image. Compared to the many good views of the eastern limb - and even the southwestern limb - this area is rarely imaged from Earth, and the limbward region even less so. Perhaps the maps should say, Serpents Lurk Here!